Actually, the description still sounds far more like underpronating than overpronating (feet roll in excessively during foot strike follow through). I know that overpronation is corrected by a stability shoe, and in cases of very large runners, by a motion control shoe, but do they make shoes for underpronation? I recommend going to runnersworld.com and trawl through looking for the section they have on feet/pronation/shoe fitting, etc. They have more info there that can help you.
This pronation/foot rolling may or may not be a problem for you, it's hard to tell. It may be that you will start to get pains or an injury and that this will reveal itself as you increase mileage and number of days running per week. But it is also possible that this is your natural running gait and that it may lead to no problems at all. I have to admit though, that this does not sound like the neutral gait that the "best" runners have and which we all learn to be envious of, so I would get it checked out by a running specialist/orthotics specialist as you need someone to analyze your gait and determine if in some way your hips and legs are currently over-compensating for your foot rolling and that this could be detrimental along the road.
Clare